Phantom electric circuit.



H B. STONE.

PHANTOM ELEG'IRIG CIRCUIT. APPLIOATION PILBD NOV. 26, 1907'.

V ,91 1,774, Patented Feb. 9, 1909.

iiirrn sfrncrns PATENT amen HENRY .B- stone, or .PRovmnNeE. RHODE ISLAND- rrinnrom' ELECTRIC mm.

no. at 1,774.

Specification of Letters gatent.

Patented Feb. 991909.

Application filed November 26, .1907. SerialNo. 403,899.

To all whom it may concern:

Be it known that I, 'HENRY B. STONE, of Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Phantom Electric Circuits; and I do hereby declare the following specification, taken in connection with the accompanying drawings,

forminga part of the same, to be a full, clear, and exact description thereof.

The invention relates to an improved system of phantoming electric circuits and is particularly designed for use in telephone systems. I

Heretofore the use of phantom circuits in tele hone systems has been limited by reason of t e fact that said phantom circuits have been introduced by bridging a repeating coil across the main metallic circuit, which method of phantoming afiects the efliciency of the main circuits and prevents the use of said main circuits for direct signaling or for telegraphic urposes.

It is the o ject of the present invention to obviate these objections to old methods of phantoming electric circuits and to produce a new and eflicient system which will not affect the eficiency of the main circuits and will not interfere with the sending of. direct currents over each of the metallic conductors two metallic telephone circuits and' a metallic phantom circuit introduced by my noyel method between said telephone circuits.

Referring to the drawings, Fig. 1 shows a repeating coil A of peculiar construction consisting 0 an iron core 1 and three'separate' insulated windings 2, 3 and 4. Two ofthese windings 2 and 3 respectively may be called the secondary windings and the winding 4' the, primary winding. The two secondarywindings 2 and 3 should be alike in resistance introduced at a way station 14. "desired part of the main circuit the repeating coil A is introduced in series by and number of turns and symmetrically arranged around the core 1 in such a manner that the magnetic effect of acurrent flowing in one direction over the winding 2 would be neutralized by an equal current flowing in the opposite direction over the winding 3. The primary winding 4 may be the same as the secondary windings 2 and 3 in resistance and the number of turns or may differ from said secondary windings in these respects as desired. The different windings are prefers ably led to convenient binding osts and the whole mounted upon a suite le base, not

shown.

Fig. 2 shows a main metallic telephone circuit composed of the two conductors 5 and 6 connecting two telephone stat-ions 7 and 8. 'I he wiring at the various stations is not shown in detail, as the same is well known and is not necessary for an understandin of the system herein described. Inserte in the main circuit adjacent each of the stations 7 and 8 is a repeating coil B consisting of two windings 9 and 10. The winding 9, for convenience called the primary winding, is connected at one end to the conductor 5 and at the other end to the conductor 6, and thus forms a bridge across that part of the main circuit which leads to the nearby station. The winding 10,"for convenience called the secondary winding, is likewise connected at one end to the conductor 5 and at the other end to the conductor 6 and thus forms a bridge across that part of the main circuit leading to the distant station. Leading from the middle point of each of the secondary windings 10- 1s a conductor 11 which leads to the stations 12 and 13 and then to the mound 9, thereby forming .an old and wdll known form of phantom circuit. With this system ofphantoming it will be seen that the main circuit is'separated or divided at each rcpeating coil into two parts insulated from each other, and hence direct currents can- .not be transmitted from one of these parts to the other.

I Will now describe myim roved method of introducing by the use 0 the repeating coil A, and in an extra or piantom circuit Fig. 2 I have shown said phantom circuit At any connecting one end of the secondary windin 2 with one part of the conductor 5 and t e other end of said winding 2 to the other part of said conductor '5. 'I he secondary winding 3 is sim larly connected in series with the conductor 6, as shown. The primary winding 4 is connected at one end to a wire 15 and at the other end to a wire 16, which wires form the way station circuit.

With the above described form of repeating coil and the manner of connecting the same in the main circuit and to the way, station. it will be seen that alternating or voice currents from station 14 passing through the primary winding 4 produce currents in the secondary windings 2 and 3 and hence in the two conductors Sand 6, which currents are alike in direction and intensity. Such currents will not be transformed by the repeating coils B, but will pass through the secondary winding 10 to the middle point, where the two currents will join and pass through the wire 11 to station 12, and thence to ground Said current would then pass through the ground to station 13 at the other end of the main circuit over wire 11,

'- secondary winding 10 at said end and conductors 5 and 6 back to secondary windings 2 and 3, thus completing the circuit.

Fig. '3 shows a way station introduced by my im roved method into a phantom circuit where o. h sides of said phantom circuit are metallic circuits. In this system the second main or trunk-circuit extending between the stations 7 and 8' is the exact duplicate of the other main circuit extending trom station 7 to station 8, as shown in Fig. 2, and the primaries of the repeating coils A and A are connected to the way station l l so that said'way station may communicate -with stations 12 or 13. When such communicationv is carried on the voice currents will pass through the primaries 4 and 4 and induce currents in the secondaries 2 and 3 of repeating coil A in one direction and in the secondaries 2 and 3 of repeating coil A in the opposite direction.- It will thus be seen that an alternating current will ass over the phantom circuit between stations 12 and 13.

In Fig. 4 I have shown my system of phantoniing as applied to trunk lines in which the common battery system is employed for signaling purposes. flhere are shown two metallic main circuits, one

leading from stations Y to 8, one at or adjacent each of said stations, and two repeating coil A are similarly connected into the main circuit leading from stations 7 to 8. The conductors 5 and 6 terminate, respectively, in the short and ions line-springs 17 and 18 of a line spring aclr, and the conductors 5 and 6' terminate, respcctiznr in the short and long line-spring 1'7 and lhe primaries 4 and 4 of the repeating coils A and A, respectively, are connected '';o-

gether on one side by the wire 1'5 and the other .ends of said primaries terminate, re spectively in the short and long line-sprir r 20 and 21 at each of the stations 12 and 13. A line-relay 22 constituting a line indicator magnet is normally included in circuit with the line springs 20 and 21 and the phantomcircuit for signaling purposes.

It is necessary that the main circuits he continued through suitable balancing apparatus to a common connection or ground, and the operators cord-circuit generally supplies this connection, wh n the cordcircuit is disconnected meant .ould he pro vided for automatically connecting the line to apparatus having practically the o electrical properties as the cord rid at. Such means are shown at each station on i main circuits, and comprise the cunt and 24, wires 25 and 26, condensers .2? ....d 28, inductive resistance coil 29 and ground E By means of this a paratus it will he soon that the insertion of tae plug attached to the cordwircuit between the line springs .17 and 18 will throw said springs out of engagement with the contacts 23 and 2-1 and thcrchy (lisconnect the halancing apparatus iron! '7 main circuit, and that the witlulrawal or" and plugs will automatically connect said hal ancing apparatus into and telephone menu.

The operation of this systom'is as follows: Voice or alternating currents at station 112 will pass through the primary winding l of repeating coil A, over wire 19, through the primary winding 4 of repeating coil 1' in the opposite direction from the directi n oi said current in coil A, and hack to station 12. if new the'current is starting from right to left through the primary winding 4 olcoil it will induce a current flowing from left to right in the secondary windings 2 and'tfl ol said coil, and said current will pass through the cord-circuit or the halancing apparatus at station 7 to the ground, through. the ground to the cord-circuit or balancing apparatus at station 8, and through the sec ondary windings 2 and 3 of the second coil A. from left to right to the main conductor. and 6 and back to the place of starting. As the current passes through the secondaries 2 and 3 of the second coil A at the left in Fig. 4, a current will he inciudcd in the rimary 4 in said coil flowing from right to sit, which current will puss throu h the sine tion 13, primary winding 4 and wire ill, thus completing the phantom circuit. In like manner the current which llous l'ronl right to left in the rimary winding 4. ol' coil A at the right in ig. t, will induce currcnu: flowing from left to right in the seconds;

E li

l ll 3) ago rents will flow over the main conductors 5 and 6, through the'secondaries 2 and 3' of coil a at the eft in Figl e, through the cordcircuit or balancing) apparatus at station 8" that alternatin oryoice currents may be sent over the p antom circuit between stations. 12 and 13. and that the main condoctors 5 and 6 and 5' and 6 can be used for direct signaling or for teiegrapliicpurposes as desired. i

What I claim as my iiiwention and desire to secure by Letters Patent is:

1. The combination, with the two conductors of a telephone circuit, ofa repeatin coil interposed between two parts of sai circuit, said repeating coil containing three separate windings, two of which windings are electrically balanced and connected in series with the two conductors of said telephone circuit in such a manner that variable or al-.

ternating currents in the third winding will induce currents-in the two balanced windin'gs and in the two conductors of the telephone circuit which are alike in direction and intensity.

2. The combination, with the two conductors of a tele hone circuit, of a repeatin coil interposed etween two parts of sai circuit, said repeating coil containing three separate windings, two of which wmdings are electrically balanced and connected in serice with the two conductors of said telephone circuit, both of said windings being connected on one side of the coil to the conductors on the correspondingside of said coil and on the other side of the coil to the conductors on that side of said coil, and the third winding connected in to a phantom circuit.

3. The combination, with two metallic telephone circuits, of two repeating coils, each of said coils being interposed between two parts of each of said telephone circuits and containing two secondary windings electrically bal &

anced and connected in series with the two sides of each of said telephone circuits, and a primary winding in both repeating coils connected together and into a phantom circuit.

4.. The combination, with two metallic tele hone circuits, of a phantom circuit in tro uced between said metallic telephone circuits by means of a series of re eating coils interposed in series into said to ephone circuits, and'means for extending said telehone circuits to a connection common to 0th metallic circuits.

v 5. The combination, with two telephone circuits, of a hantom c'rcuit introduced between said te ephone circuits by means of-a series of re eating coils interposed in series into said to ephone circuits, and a balancing apparatus in each of said telephone circuits.

6. The combination, with two telephone circuits, of a phantom circuit introduced be tween said to ephone circuits by means of a series of repeating coils interposed in series into said telephone circuits, and a balancing apparatus adapted to beautomatically connected into or disconnected from said telephone circuits.

7 The combination, with two metallic telephone circuits, of a phantom telephone circuit comprising a series of repeating coils inter osed in series in both of said metallic telep one circuits, and a balancing a paratus'at both ends of each of said metal ic cir- HENRY B. STGNE.

Witnesses:

W. H. Tnuns'ron, J. H. Tnuns'rou. 

